Veterinary instrument.



J. S. VINNEDGE.

VETERINARY INSTRUMENT.

APPLICATION man MAY 13. 1915.

1 ,162,669. Patented Nov. 30,1915.

Witnesses Inventor;

i iZ/Zize V t Attorneys.

ENTTED TATES PATENT @FFTQE.

JOHN S. VINNEDGE, OF 0RD, NEBRASKA.

VETERINARY INSTRUMENT.

Application filed May 13, 1915.

To all whom it may concern:

Be it known that I, JOHN S. VINNEDGE, a citizen of the United States, residing at Ord, in the county of Valley and State of Nebraska, have invented a new and useful Veterinary Instrument, of which the following is a specification.

The device forming the subject matter of this application is a trephine adapted to be employed in veterinary surgical operations,

calling for terebration of the cephalic bones of a horse or other animal.

' The invention aims to provide a device of this type which will cut rapidly, remain sharp, clear itself readily, admit of a thorough cleansing or sterilization, and withstand the severe usage to which structures of this sort are subjected.

It is within the province of the disclosure to improve generally and to enhance the utility of devices of that type to which the present invention appertains.

lVith the above and other objects in view which will appear as the description prooeeds, the invention resides in the combination and arrangement of parts and in the details of construction hereinafter described and claimed, it being understood that changes in the precise embodiment of the invention herein disclosed can be made within the scope of what is claimed, without departing from the spirit of the invention.

In the accompanying drawing Figure 1 shows the invention in side elevation; Fig. 2 is an end elevation wherein remote parts are omitted; Fig. 3 shows the invention in side elevation, viewed at right angles to the showing of Fig. 1, parts being broken away; Fig. 4: is a detail enlarged from Fig. 1.

The instrument forming the subject matter of this application preferably is fashioned from metal throughout and comprises a shank 1 carrying a socket 2 in which is firmly mounted a transverse handle 3. The shank 1 terminates in a flattened head 4. terminally provided with a centering bit 5 which is pointed, and ordinarily rectangular in cross section, in order that the centering bit may cut a passage for itself in the bone. The head 4 is terminally provided with cut- Speeification of Letters Patent.

Patented Nov. 30, 1915.

Serial No. 27,899.

' ting bits 6 located upon opposite sides of the centering bit 5, the ends of the cutting bits 6 being beveled in opposite directions, as shown at 7, to define transverse cutting edges 8. The lateral edges of the cutting bits 6 are beveled toward the rear faces of the cutting bits as shown at 9 and are inclined as shown at 10, toward the axis of the shank 1, thereby to afford clearance.

The centering bit 5 has longitudinal slant faces 15 which extend across a transverse plane P-P disposed at right angles to the axis AA of the centering bit and tangential to the cutting edges 8. The center ing bit 5, therefore, tends to retard the cutting bits 6, so that these bits do not pass too rapidly through the bone and strike into the brain.

Having thus described the invention, what is claimed is A veterinary trephine terminated in a flat head provided with lateral cutting bits and with an intermediate centering bit projecting but slightly beyond the cutting bits thereby to avoid an injury to the brain structure before the cutting bits have sevcred the bone, the lower ends of the cutting bits being beveled continuously in opposite directions from one side face of the head to the opposite face thereof to define cutting edges, the centering bit having longitudinal. slant faces defining a point, the said slant faces being extended across a transverse plane disposed at right angles to the axis of the centering bit and tangential to the cutting edges, thereby to retard the advance of the cutting edges into the bone, the longitudinal edges of the head diverging toward the working end of the trephine and being provided with longitudinal beveled surfaces which slant toward the rear faces of the cut ting bits and intersect the beveled faces which define the cutting edges.

In testimony that I claim the foregoing as my own, I have hereto affixed my signature in the presence of two witnesses.

JOHN S. VINNEDGE.

Witnesses:

J. H. CARSON,

RAYMOND HORKY.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents.

Washington, D. G. 

